Distance measuring system

Abstract

An imaging device includes a plurality of imaging elements, wherein each of the plurality of imaging elements includes: a plurality of pixels containing impurities of a first conductivity type; an element separation wall surrounding the plurality of pixels and provided so as to penetrate a semiconductor substrate; an on-chip lens provided above a light receiving surface of the semiconductor substrate so as to be shared by the plurality of pixels; and a first separation portion provided in a region surrounded by the element separation wall and separating the plurality of pixels, the first separation portion is provided so as to extend in a thickness direction of the semiconductor substrate, and a first diffusion region containing impurities of a second conductivity type opposite to the first conductivity type is provided in a region positioned around the first separation portion and extending in the thickness direction of the semiconductor substrate.

What is claimed is: 
     
         1 . An imaging device comprising:
 a semiconductor substrate; and   a plurality of imaging elements arranged in a matrix on the semiconductor substrate along a row direction and a column direction, and configured to perform photoelectric conversion on incident light, wherein   each of the plurality of imaging elements includes:   a plurality of pixels provided adjacent to each other in the semiconductor substrate and containing impurities of a first conductivity type;   an element separation wall surrounding the plurality of pixels and provided so as to penetrate the semiconductor substrate;   an on-chip lens provided above a light receiving surface of the semiconductor substrate so as to be shared by the plurality of pixels; and   a first separation portion provided in a region surrounded by the element separation wall to separate the plurality of pixels,   the first separation portion is provided so as to extend in a thickness direction of the semiconductor substrate, and   a first diffusion region containing impurities of a second conductivity type opposite to the first conductivity type is provided in a region positioned around the first separation portion and extending in the thickness direction of the semiconductor substrate.   
     
     
         2 . The imaging device according to  claim 1 , wherein
 two first separation portions are provided,   the two first separation portions extend to separate the plurality of pixels and face each other when viewed from above the light receiving surface, and   the first diffusion region is provided in a region between the two first separation portions.   
     
     
         3 . The imaging device according to  claim 2 , wherein
 the two first separation portions protrude from the element separation wall along the column direction when viewed from above the light receiving surface.   
     
     
         4 . The imaging device according to  claim 3 , wherein
 the two first separation portions are provided so as to be positioned at the center of the imaging element in the row direction when viewed from above the light receiving surface.   
     
     
         5 . The imaging device according to  claim 3 , wherein
 the two first separation portions are provided at positions shifted from the center of the imaging element by a predetermined distance in the row direction when viewed from above the light receiving surface.   
     
     
         6 . The imaging device according to  claim 2 , wherein
 the two first separation portions protrude from the element separation wall along the row direction when viewed from above the light receiving surface.   
     
     
         7 . The imaging device according to  claim 6 , wherein
 the two first separation portions are provided so as to be positioned at the center of the imaging element in the column direction when viewed from above the light receiving surface.   
     
     
         8 . The imaging device according to  claim 6 , wherein
 the two first separation portions are provided at positions shifted from the center of the imaging element by a predetermined distance in the column direction when viewed from above the light receiving surface.   
     
     
         9 . The imaging device according to  claim 2 , wherein
 lengths of the two first separation portions are the same when viewed from above the light receiving surface.   
     
     
         10 . The imaging device according to  claim 2 , wherein
 lengths of the two first separation portions are different from each other when viewed from above the light receiving surface.   
     
     
         11 . The imaging device according to  claim 2 , further comprising:
 two second separation portions extending along a direction different from a direction in which each of the two first separation portions extends, and facing each other when viewed from above the light receiving surface, wherein   each of the two second separation portions is provided so as to extend in the thickness direction of the semiconductor substrate, and   a second diffusion region containing impurities of the second conductivity type is provided in a region between the two second separation portions.   
     
     
         12 . The imaging device according to  claim 2 , further comprising
 one or more additional walls provided between the two first separation portions.   
     
     
         13 . The imaging device according to  claim 12 , wherein
 the additional wall is provided so as to penetrate the semiconductor substrate.   
     
     
         14 . The imaging device according to  claim 12 , wherein
 the additional wall is provided to extend from the light receiving surface to a middle of the semiconductor substrate along the thickness direction of the semiconductor substrate.   
     
     
         15 . The imaging device according to  claim 2 , wherein
 the element separation wall and the two first separation portions are made of the same material.   
     
     
         16 . The imaging device according to  claim 2 , wherein
 the element separation wall and the two first separation portions are made of materials different from each other.   
     
     
         17 . The imaging device according to  claim 2 , wherein
 the plurality of imaging elements further includes a light shielding film provided along the element separation wall on the element separation wall when viewed from above the light receiving surface.   
     
     
         18 . The imaging device according to  claim 17 , wherein
 the light shielding film is provided along the two first separation portions.   
     
     
         19 . An imaging device comprising:
 a semiconductor substrate; and   a plurality of imaging elements arranged in a matrix on the semiconductor substrate along a row direction and a column direction, and configured to perform photoelectric conversion on incident light, wherein   each of the plurality of imaging elements includes:   a plurality of pixels provided adjacent to each other in the semiconductor substrate and containing impurities of a first conductivity type;   a pixel separation wall that separates the plurality of pixels; and   an on-chip lens provided above a light receiving surface of the semiconductor substrate so as to be shared by the plurality of pixels,   the pixel separation wall is provided so as to extend from the light receiving surface to a middle of the semiconductor substrate along a thickness direction of the semiconductor substrate, and   a region positioned on a side opposite to the light receiving surface with respect to the pixel separation wall in the thickness direction of the semiconductor substrate contains impurities of a second conductivity type opposite to the first conductivity type.   
     
     
         20 . An electronic device comprising:
 an imaging device including:   a semiconductor substrate; and   a plurality of imaging elements arranged in a matrix on the semiconductor substrate along a row direction and a column direction, and configured to perform photoelectric conversion on incident light, wherein   each of the plurality of imaging elements includes:   a plurality of pixels provided adjacent to each other in the semiconductor substrate and containing impurities of a first conductivity type;   an element separation wall surrounding the plurality of pixels and provided so as to penetrate the semiconductor substrate;   an on-chip lens provided above a light receiving surface of the semiconductor substrate so as to be shared by the plurality of pixels; and   a first separation portion provided in a region surrounded by the element separation wall to separate the plurality of pixels,   the first separation portion is provided so as to extend in a thickness direction of the semiconductor substrate, and   a first diffusion region containing impurities of a second conductivity type opposite to the first conductivity type is provided in a region positioned around the first separation portion and extending in the thickness direction of the semiconductor substrate.